Method and machine for rolling fins on tubes



March 14, 1933. R. K. HOPKINS METHOD AND MACHINE FOR ROLLING FINS ON TUBES 2 Sheets-Sheet .l

Filed Nov. 14, 1929 ATTORNEY.

March 14, 1933. R K HomNs 1,901,516 v METHOD AND MACHINE FOR ROLLING FINS ON TUBES Filed Nov. 14, 1929 2 Sheets-Sheet 2 w- 1 1 n-1:111x::: 111111 1:1,.

INVENTOR ROBERT K. HOP/(0V5 BY W/M ATTORNEY Patented Mar. 14, 1933 UNITED STATES PATENT OFFICE. l

manner 1:. norxmgor s'r. enoaen, new YORK, Assmnon. TO run I. w. IKELLOGG courm, or new Yoax, rr. 1., .A' coarom'rron or nmwm m0!) AND CHINE FOR ROLLING IINS ON TUBES Application fled November 14, 1929. Serial No. 407,041.

This invention-relates to a method and.

means for forming tubes or cylinders having integral radiating fins or external flanges of substantial height.

An object of the invention is to provide a machine for forgingor displacing the metal of a tube or cylinder to form a fin or fins thereon to increase the radiating surface of the tube or cylinder and also its strength whereby its ability to withstand large. pressures is increased.

A feature of the invention resides in feeding a tube blank or cylindertoward a roll or a plurality of rolls, while simultaneously therewith the tube is given a rotary motion.

The resultant motion thus imparted-to the tube causes the rolls associated therewith to displace the metal of the tube radially to form a spiral fin or flange thereon. The rolls are free to idle upon their axes, and their rotary motion is provided by the rotary motion of the tube with which they are in contact. The rolls are mounted on axes equally spaced about the tube and are progressively spaced along the tube a distance suflicient to permit the second and third rolls to pick up or follow in the groove formed by the first roll. Each roll has but a single transverse flange, so

that the metal of the tube may be'displaced1 both longitudinally and radially without being confined in any way by the rolls. As .the metal of the tube sufiers a certain amount of longitudinal displacement in operations of this character the second and. third rolls are allowed a suflicient amount of longitudinal play in order that they may readily enter and not disturb the groove which has already been started by the preceding roll.

A better understanding of the invention may be had by reading the following descrip-. tion together with the accompanying drawingsof which Fig. 1 represents a side elevation partly in section of a machine for carrying out the invention. Fig. 2 is a section on line22 of Fig. 1 showing the manner in which the 'rolls "are spaced about the blank which is being rolled, an

Fig. 3 is a half section .on line 3-3 and a half section on line 44 of Fig. 1 showing the means for feeding the blank in the ma- I chme '-Referring to the drawings, a machine em-.

upon the base of the machine while the stand-v ard 5 is adapted to move along the base. As

the standard 5 must rest firmly upon the base of the machine a dovetail joint may be provided which limits the standard 5 to longitudinal motion. Thestandard 4 has two upare journaled, although it is to be understood that the invention is not to be limited to any particular number of rolls. 4

-, rights 21 and 22 in which the rolls 7, 8 and 9 A hollow blankor tube 10 is supported in the machine upon' a mandrel 11 which is supported b and is free to rotate in hearings in the stan ards 3, 5 and 6.

Some suitable,v means, as for instance a pin 12, passing through holes in the blank and the mandrel is provided in order that the blank may be rotated integrally with the mandrel. The mandrel is equipped with a collar 13 which butts against the blank 10 and imparts horizontal motion thereto when the standard 5 is moved along the ways by. mtxns hereafter described.

length of the longest blank tube upon which the machine is designed to operate. As the shaft 19 is rotated the screwing action of the thread imparts horizontal motion to the standard 5 which in turnmoves the blank tube 10 toward the rolls. Ports 23 and 24.-

are provided in the uprights 21 and 22 supporting the rolls in order that the tube may pass freely therethrough.

When'tliree rolls are used they are pref- 10, asshown-in Fig. 2, and are also'spaoed ar 15 is keyed tothe mandrel by means of a ey 16 seated in a long keyway 17 mwer as for instance a motor not shown.

- erably spaced equi-distantly about the tube 1'00 7. Between the hubs of the rolls 8 and 9 and the standards 21 and 22 is provided a tolerance for permitting longitudinal movement of the rolls to accommodate for the longitudinal flow of the metal in the tube 10 during the rolling process. The flanges upon the rolls are preferably equal in diameter, although in some instances it may be desirable to increase the size of the successive flange. v

The distance between the standards 3 and 5 may be adjusted so that it is sufliciently great to accommodate the tube which is being rolled. At the beginning of the rolling operation the'mandrel extends to the right of the standard 6 a distance equal to orgreater than the length of the tube so that as the mandrel moves to the left during the rolling operation, the'key associated with the gear 15 is always in the keyway 17.

In operation a blank tube is heated to a suitable rolling temperature, placed upon the mandrel and pinned or otherwise fastened thereto. At the beginning of the rolling operation the standard 5 is at its extreme right position. Aspower is applied to'the shaft 19 the standard 5 is moved to the left thus causing the collar 13 to move the blank in the horizontal direction toward the rolls. At the same time the gear 18, which meshes with the car 15, drives the mandrel which in turn imparts a rotarymotion to the tube on account of its connection therewith by the pin 12. The rotary motion of the tube blank as it advances toward the rolls imparts a rotary motion to the latter, thus performing the rolling process. The hot tube first comes in contact with roll 7 which displaces the metal of the tube causing it to flow up the sides of the roll to form the fin. When the tube has rotated through120 it has been pushed forward by the standard 5 a distance suflicient to pick up the second roll. The second roll is thuspositioned beyond the first a distance equivalent to one-third the pitch of the spiral fin.

The height of the fins maybe regulated by proportioning the sizes of the flanges upon the rolls and the pitch and thickness of the spiral fin may beregulated by proporti'oning the sizes of the gears 18 and 15. Of course,

it is to be understood that it is not necessary to heat the entire blank at once but the heating may be confined to the portion of'the tube being worked and the rolling done in stages.

The invention also is not limited to a case in which the tube 'is advanced toward the rolls, since if desired the standards upon which the rolls are mounted may be made many movable and capable of being advanced toward the tube blank. This could readily be done in the embodiment of my invention shown by eliminating the standard. 5 and permitting the threaded portion of the screw 20 to extend through the standard 4. Thus if the screw were of the proper type the rotation of the shaft 19 would cause the tube blank to rotate and the rollsto be advanced toward it. In other words, it is simply the case of relative motion, between the rolls and the blank and a case is still conceivable where the roll housing could be rotated about the tube and advanced with respect thereto or simply rotatedabout the tube while the latter is advanced toward the rolls.

Thus, although a single embodiment of the invention'has been shown it is capable of modifications by those skilled in the art, and is to be limited therefore only by the prior art and the scope of the appended claims.

I claim:

1. In a machine for forming integral radiating fins ofsubstantial height upon a tube or the like, a plurality of rolls ositioned about said tube for forming said said rolls forming and operating in the same track, means for rotating said tube about its longitudinal axis, means for providing relas, all of tive motion between'said rolls and said tube plurality of rolls each having a single trans-v verse flange, said rolls being positioned equidistantly about said blank and further positioned to follow in the same track, means for rotating said tube and advancing it toward said rolls to displace the outer material. of.

said tube radially to form said fins.

3. Apparatus for making tubes or the like with integral radiating fins comprising a mandrel for supporting the hollow blank, a plurality of said blank and further positioned to follow in the same, track, means for rotating said tube, means for providing relative longitu-.

dinal motion between said tube and said rolls, the resultant relative movement between said tube and said rolls causing said rolls to displace the outer material of said tube radially to form'a spiral fin.

4. In a machine for forming integral radiating fins of substantial height 'upo'n a'tube or the like, a plurality of rolls positioned about said tube for forming said fins, certain of said'rolls having longitudinal axial play, said rolls operating in the same track. means for rotating said tube about its longitudinal rolls each having a single transverse flange, said rolls being positioned about v the rolling axis, means for providin relative motion between said rolls and sai tube longitudinally of the latter and simultaneously with said rotary motion, the rollin action of said rolls being imparted thereto y the movement of said tube.

5. In a machine for forming integral radiating fins of substantial height upon a tube or the like, a plurality of rolls ositioned about said blank for forming sai fins, said rolls being positioned to operate in the same track, mounting means for said rolls, said mountin means'permitting lon 'tudinal movement 0 certain of said rolls a ong their axes, means for imparting a rotary and longitudinal movement to said tube toward said rolls to displace the metal of said tube to form a fin, the axial displacement of certain of said rolls providing for the longitudinal flow of the metal in the tube during the rolling procew.

' 6. The method of forming a fin o substantial size upon a tube to increase the radiating area thereof which com rises formin a r continuous groove on the tu by a lural ity of simultaneous rolling o rations w 'ch consecutively increase the epth of the groove and the height of the-fin between the groove by displacement of the tube material at the sides of the groove.

' 7. In a machine for formin integral radiating fins upon a tube or the hke; a plurality of rolls positioned about the tube for forming said fins, all of said rolls forming and operating in the same track; means for causing relatlve rotary motion between said tube and rolls; means for causin relative motion between said rolls and tube ongitudinally of the latter and simultaneously with said rotary motion, the relative rotary movement 0 between the tube and rolls causing rotation of the latter. 8. In a machine for forming integral radiatin fins upon atube or the l' e, a plurality of trac g rolls positioned about the tube for a forming said fins,.and means for impartin motion to the tube said rolls bein actuat by the movement of said tube, one o said rolls operating to form a groove and the other roll or rollers acting in saidgroove between said fins to progresively increase the depth of said groove and displace the material of said groove for forming said fins. In testimony whereof, I have signed my name to this specification this 12th day of November, 1929. ROBERT K. HOPKINS. 

